Full-service broadband cable modem system

ABSTRACT

A method and system are disclosed for enabling full-service communications between a full-service cable modem termination system (fsCMTS) and a plurality of full-service cable modems (fsCM&#39;s) for a conventional two-way hybrid fiber-coax (HFC) cable television network. Full-service communications include data, voice and video. Video includes broadcast quality MPEG-2 transport packet streams and Internet protocol media streams. A multi-channel full-service media-access-control (fsMAC) coordinates the access to the shared upstream and downstream channels. At lease two downstream channels and at least two upstream channels are provided. Several MAC management messages are defined to enable multi-channel full-service MAC domain to be defined and to enable packet-by-packet true seamless channel change. Multiple upstream channels can be used in various ways to best optimize the use of the spectrum for meeting the quality-of-services needed by different services.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The application is a continuation of provisional applicationfiled on Apr. 14, 2001, Ser. No. 60/283,842, which is incorporatedherein by reference.

FIELD OF THE INVENTION

[0002] The invention relates to the “last mile” broadband digitalcommunications systems capable of delivering full-service of voice,video and data to residential and commercial premises. More particularlythe invention relates to the field of improvements in the media accesscontrol (MAC) protocol of a full-service cable modem system that usesmultiple downstream and upstream channels.

BACKGROUND OF THE INVENTION

[0003] For the last few years, cable modem systems based ondata-over-cable service specifications have been accepted as a “lastmile” high-speed data solution for the consumers.

[0004] A two-way Hybrid Fiber-Coax (HFC) cable network is aninfrastructure capable of supporting multiple overlaying networks, viz.analog or digital video service, high-speed data, and telephony service.These services use different band of the available spectrum in thedownstream and upstream directions, and each service has its ownoperations and provisioning infrastructure. At customer premises, afull-service subscription requiring multiple boxes of customer premisesequipment (CPE) such as a set top box, telephone network interface unit,and cable modem. These overlaying services are inefficient in termsincrease the cost of operations and cost of consumer ownership.

[0005] Convergent Network

[0006] It has been highly desirable to have a converged network, capableof delivering voice, video and data in a unified communicationsinfrastructure.

[0007] Although later versions of data-over-cable media-access-control(MAC) have quality-of-service (QoS) capability by using polling, theprotocol essentially is based on sharing an upstream and a downstreamchannel. Switching users among channels is complex and slow.

[0008] Moreover, the cable modem has severe limitations when it comes tosupport digital video services. Conventional digital video (broadcast orvideo on demand) requiring more stringent bit-error-rate than dataservices and high bit rate of approximately 20 Mbps per HDTV moviechannel, significantly impacting the capacity of the other servicessince they reside in the same downstream channel.

[0009] Upstream Limitations

[0010] The upstream bandwidth of the HFC network is limited by twofactors: first, the amount of available spectrum in the upstream in a“sub-split” HFC cable plant is between 5 to 42 Mhz in the US. Because ofingress interference, a good portion of the spectrum is not suitable forwide-band (e.g. 3.2 Mhz or 6.4 Mhz per channel) and higher-ordermodulations (e.g. 16, 32, or 64 QAM) to achieve a high capacity for theupstream channel in use. If a 6.4 Mhz channel is used, only6.4/(42−5)=17% of the upstream spectrum is used. The other 83% of thespectrum (in particular for frequencies below 10 MHz) is often unused.Conventional data-over-cable MAC is quite limited in handling multiplechannels, in increasing the capacity, and providing the quality ofservice (QoS) required by different services.

[0011] Moreover, since each upstream channel must support the packetsgenerated by different services with different QoS requirements, it isvery difficult to achieve high channel utilization under dynamicallychanging traffic conditions. In particular, the overhead of the MACmanagement packets such as bandwidth request and initial calibration canbe significant and complicate the scheduling efficiency of cable modemtermination system (CMTS).

[0012] Conventional data-over-cable MAC protocol relies on some form ofpolling to achieve QoS goal of meeting bandwidth, latency and jitterrequirements. For a polling interval of 2 ms, each upstream channelrequires about 270 Kbps of downstream bandwidth for the MAC operation.This represents a significant amount of bandwidth from the downstreamchannel Therefore, scalability of using multiple upstream channels inconventional data-over-cable is quite limited.

[0013] Broadcast Quality Digital Video

[0014] Although the HFC network has sufficient bandwidth to supportdelivery of a full spectrum of services including data, telephony andvideo, these services currently are separate infrastructures provisionedby a service provider. As a result, these are sub-optimal uses of theHFC spectrum and costly duplication of equipment at the head end and atcustomer premises. Recently voice-over-IP using a same IP protocolenables convergence of voice and data. However, video service remains aseparate infrastructure.

[0015] Therefore, there is an unmet need for a unified communicationsystem that can provide the full need of providing broadband Internetaccess, IP telephony, broadcast quality digital video over the same HFCsystem.

[0016] Therefore, there is an unmet need for a MAC that can be used toimplement a full-service cable modem system to fulfill the fullpotential of a HFC network for delivery voice video and datacost-effectively to the home and business.

[0017] It will be realized after the detailed description of theinvention to overcome the limitations of conventional cable modem systemby the novel MAC and system architecture that allow a highly efficientand scalable access method that can be used to deliver simultaneouslyinteractive digital video, telephony and high speed internet access aswell as interactive gaming shared by large number of users. That the MACfully utilizes the upstream and downstream spectrum enabling serviceprovider economically deploys the services without a forklift upgrade tothe HFC cable plant currently deployed for conventional cable modemservice. The unified full service communication system will reduce costof providing three separate provisioning system for video, data andvoice, reduce head end equipment and at the same time reduce the numberof on-premises equipment from three to one.

[0018] It is an object of the present invention to overcome thedisadvantages of the prior art.

BRIEF SUMMARY OF THE INVENTION

[0019] This and other objects are achieved by the present invention. Inaccordance with the present invention a full-service cable modem (fsCM)system capable of delivering video, data and voice over a two-way hybridfiber-coaxial cable network is described.

[0020] A high-capacity, high-efficiency multi-channel full-service MAC,capable of supporting multiple upstream and downstream channels, enablesthe fsCM system 100 to deliver a full spectrum of services presentlyrequiring multiple delivery systems. The video can be a combination ofhigh-quality broadcast MPEG-2 movie or IP video streaming, with therequired quality of service.

[0021] Further, multiple channels can be used to multiplex packets ofall types, enabled by a true seamless channel change described in thisinvention, maximizing statistical multiplexing gain. Packet-by-packetchannel switching enables fast recovery from a channel failure, asrequired a high-availability fault-tolerance cable modem system.

[0022] The fsCM system 100 consists of, according to the preferredembodiment, illustratively two downstream channel (DCPC and DPC1), twoupstream payload channels (UPC1 and UPC2), three upstream controlchannels (UCC1, UCC2, UCC3) that connect a fsCMTS in the head-end and aplurality of fsCMs at subscriber sites.

[0023] FsCM uses DCPC for downstream MAC management messages as well asfor payloads (MPEG-2 TS or IP packets) and DPC1 for downstream payloadchannel to deliver high quality MPEG-2 video or IP packets.

[0024] The present invention further includes downstream MAC managementmessages MMAP 900 and MDCD 1000 to enable fsCMTS to allocate upstreamtransmission to any of the multiple upstream channels on apacket-by-packet basis, and allow multiple-channel MAC domain to bechanged quickly to adapt changing traffic on the network.

[0025] The methods and apparatus described herein implement a novel andunique facility that provides for efficient access of a full-servicecable modem network capable of simultaneously servicing thecommunication needs of internet access, telephony, interactive andon-demand digital video to a large number of users over a conventionalHFC network.

[0026] FsCM uses DCPC for downstream MAC management messages as well asfor payloads (MPEG-2 TS or IP packets) and DPC1 for downstream payloadchannel to deliver high quality MPEG-2 video or IP packets).

[0027] The present invention further includes downstream MAC managementmessages MMAP 900 and MDCD 1000 to enable fsCMTS to allocate upstreamtransmission to any of the multiple upstream channels on apacket-by-packet basis, and allow multiple-channel MAC domain to bechanged quickly to adapt changing traffic on the network.

[0028] The methods and apparatus described herein implement a novel andunique facility that provides for efficient access of a full-servicecable modem network capable of simultaneously servicing thecommunication needs of internet access, telephony, interactive andon-demand digital video to a large number of users over a conventionalHFC network.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 is a block diagram illustrating an embodiment full-serviceCable Modem System;

[0030]FIG. 2 is a block diagram of a full-service cable modem;

[0031]FIG. 3 is a diagram illustrating the frequency channel plan for anexample full-service cable modem system;

[0032]FIG. 4 is a block diagram illustrating the structure of SYNCmessage 500;

[0033]FIG. 5 is a block diagram illustrating the structure of CREQmessage 600;

[0034]FIG. 6 is a block diagram illustrating the structure of CRSPmessage 700;

[0035]FIG. 7 is a block diagram illustrating the structure of BREQmessage 800;

[0036]FIG. 8 is a block diagram illustrating the structure of MMAPmessage 900;

[0037]FIG. 9 is a block diagram illustrating the structure of MDCDmessage 1000; and

[0038]FIG. 10 is a flow diagram illustrating of the fsCM initialization;and

[0039]FIG. 11 is a flow diagram illustrating the upstream transmissionprocess using contention BREQ 800.

DETAILED DESCRIPTION OF THE INVENTION

[0040] Refer to FIG. 1 for a preferred embodiment of a multi-channelfsCM system 100. A fsCMTS 102, typically located at a head end 101, isconnected to the fiber-part of a two-way HFC network 104 through anelectrical to fiber interface (not shown). A remotely located fsCM 106is connected to the coax 402 part of the HFC 104. The downstreamspectrum (typically 50 to 850 Mhz) is divided into typically 6 Mhzchannels in the downstream for NTSC cable systems. The upstream spectrumtypically ranges from 5 to 42 Mhz in North America, and the upstreamchannel bandwidth varies typically from 160 KHz to 6.4 Mhz. Thearchitecture and topology of a modern two-way HFC cable plant are knownin the art and will not be repeated here.

[0041] In this example, also referring to FIG. 3, there are twodownstream channels: a downstream control and payload channel DCPC 147and a downstream payload channel DPC1 137, and five upstream channels:upstream control channels UCC1 174, UCC2 176, UCC3 178 and upstreampayload channels UPC1 182 and UPC2 184. The exemplified channelfrequencies are illustrated in FIG. 3, in which channel centerfrequencies for DCPC 147, DPC1 137, UCC1 174, UCC2 176, UCC3 178, UPC1182 and UPC2 184 correspond to f1, f2, f3, f4, f5, f6, f7 respectively.The center frequencies for DCPC 147 and DPC1 137 are controlled by thecorresponding frequency-agile up-converters 146 and 136. The UCC's 174,176 and 178 channel center frequencies and channel bandwidths arecontrolled by a burst transmitter 194. The UPC's 182 and 184 centerfrequencies and channel bandwidths are controlled by another bursttransmitter 196. Illustratively, the UCC's use narrower channelbandwidths and robust modulation schemes such as QPSK or BPSK that canbe located in the noisier portion of the upstream spectrum. The“cleaner” part of the upstream spectrum are normally used by UPC's sothat higher order of modulations such as 16 to 64 QAM can be usedreliably for higher throughput for payloads. In an alternativeembodiment, a single upstream frequency-agile programmable bursttransmitter can multiplex the transmission of control and payloadbursts.

[0042] Through an IP network interface 122, the fsCMTS 102 is connectedto a video server 108 for MPEG-2 digital video services, to a managedInternet backbone 112 for connection to a Public Switched TelephoneNetwork PSTN 113, or other voice-over-IP networks for telephonyservices, to an Internet backbone 114 for high-speed data services, andto an Intranet IP network 116 for access to provisioning and networkmanagement servers as part of the fsCMTS system operation. The IPnetwork interface is also connected to the video server 108 forproviding IP connectivity for video-related network management andillustratively, for upstream traffic generated by set-top boxes 530.

[0043] Digital video traffics, generated by the video server 108,packetized into MPEG-2 transport streams TS 150, 152 are combined withfsCMTS MAC messages including SYNC 500, MMAP 900, MDCD 1000 and IPpayload packets 154 in downstream transmitters 132, 142, which areoutputted to downstream modulators 134, 144. The intermediate frequencyoutputs of the modulators 134, 144 are up converted to the desiredcenter frequencies by up converters 136 and 146. The radio frequency RFoutputs of the up converters 136 and 146 are then transmitted throughthe HFC plant 104 into downstream receivers 470, 420 of fsCM's 106 viathe coaxial 402 portion of the HFC 104.

[0044] The downstream modulators 134, 144 typically are specified tocomply with ITU J83 Annex A, B, or C depending on nationality. Othermodulation and forward error correction (FEC) formats are possible.

[0045] IP packets 154 are encapsulated in MPEG2-TS using a unique packetidentifier PID (1 FFE hexadecimal for data-over-cable) beforetransmitting downstream.

[0046] The time base in the fsCMTS 102 and in the remote fsCMs 106 aresynchronized by periodically sending a captured time-stamp value of atime-stamp counter 130 driven by a time-stamp frequency source 128. Thetime-stamp value is encapsulated in a MAC management message (SYNC 500),which is in turn encapsulated into a MPEG2-TS and merged with the otherTS before delivering to the downstream modulator 134. The method ofsynchronization using time-stamped message is known in the art.

[0047] The SYNC 500 is transmitted in all downstream channels so as toenable seamless switching of downstream channels.

[0048] The DCPC 147 carries MAC management messages including a MMAP 900and MDCD 1000 which are essential for the multi-channel MAC operationand their significance will be understood when they are described indetail below.

[0049] A full-service MAC (fsMAC) has two parts: a fsMAC-CM 192 and afsMAC-CMTS 124, which are located in the fsCM 106 and fsCMTS 102respectively. The fsMAC's role is to co-ordinate the dispatch ofdownstream IP packets and fsMAC management messages; another role is toco-ordinate the efficient and orderly transmission of upstream burstsusing the two upstream burst transmitters 194 and 196.

[0050] One of the transmitters 194 is used for transmitting fsMACmanagement packets such as calibration and bandwidth requests. The othertransmitter 196 is for transmitting payload of IP packets 199 receivedfrom a CPE interface 197.

[0051] More specifically, the transmitter 194 is used to transmit burststo UCC1 174, UCC2 176 or UCC3 178 using burst profiles communicated tofsMAC-CM 106 by fsMAC-CMTS 124 by sending down MDCD 1000. Similarly, thetransmitter 196 is used to transmit bursts to UPC1 182 or UPC2 184 usingother burst profiles. The fsCM 106 learns the characteristics of burstprofiles by listening to the MDCD message 1000 and uses the burstprofile and time to transmit by decoding the MMAP message 900.

[0052] At the fsCMTS 102, corresponding to these transmitters in thefsCM 106, there are frequency-agile programmable burst receivers thatwill receive, demodulate and recover the packets received. These packets(including collision detection information, if any) will be inputted tothe fsMAC-CMTS 124.

[0053] Full-Service Cable Modem Detail

[0054]FIG. 2 is a block diagram illustrating an embodiment of the fsCM106. The RF signal enters the fsCM 106 at the coax 402. The RF isdivided into two paths by RF splitter 404. Each RF path after thesplitter is connected to diplex filters 410, 460. Diplex filer 410passes high frequency downstream RF signal 412 to DPC1 downstreamreceiver 420, whose output is a MPEG-2 transport stream TS1 422 into apacket identifier (PID) de-multiplexing unit 424. Demux unit 424separates the data-over-cable TS 426 from the conventionalaudio/video/data TS 423 by examining the PID value. Data-over-cable TS426 is identified by a value of 1FFE (hexadecimal). The audio/video/dataTS 423 associated with a program (e.g. movie) is directed to aconventional MPEG-2 decoder 428 for generating audio/visual signals.Outputs from the decoder 428 can be of digital television DTV 430, orstandard analog signal 434 (composite video or NTSC modulated RF) forconnection to conventional television receivers or video monitors.

[0055] Alternatively, the TS 423 can interface to a digital set-top boxusing IEEE 1394 (not shown), or other high-speed connections. Anotheralternative is to send the MPEG-2 audio/video/data TS 476 to FSMAC-CM192, where the TS is encapsulated in IP (MPEG-2 over IP) and forwardedto a home network 508 via CPE interface 504. A digital set-top box 503attached to the home network 508 can decode the MPEG-2 TS.

[0056] Another RF path 405 passes through diplex filter 460. DownstreamRF signal 462 is tuned to DCPC 147 and processed by a second downstreamreceiver 470, whose output is another MPEG-2 transport stream TS 472,which is inputted to the PID demux unit 424, which in turn separates thedata-over-cable TS 476 from the audio/video/data TS 473.

[0057] Data-over-cable TS 426 is processed in a downstream processingunit 502 to recover data-over-cable packets, consisting of MAC messagesand IP payload packets, before entering a fsMAC-CM. MAC messages areprocessed by fsMAC-CM 192. IP payload packets are forwarded to CPEdevices attached to the home network 508, subjected to filtering rulesby the CPE interface 504, which is illustratively, an Ethernet networkinterface. Specifically. IP packets are subjected to filtering rules inthe packet forwarding engine within CPE interface 504 using bridging orrouting rules. The IP packets are forwarded to a CPE devices such as apersonal computer 514, an Internet Appliance 512, Multimedia TerminalAdaptor 516 for voice-over-IP telephony 518, FAX 522, video conferencing520 and other media streaming services using any home networkinginfrastructure 508 (e.g. 10/100 Base-T Ethernet, USB, HPNA, WirelessLAN, HomePlug etc.)

[0058] Upstream IP packets from CPE devices 512, 514, 516, 530 aresubjected to filtering by the packet forwarder within the CPE interface504, and then are queued at upstream processing unit 506. There are twoupstream burst transmitters in this embodiment: one for Upstream ControlChannel (UCC) 194 and Upstream Payload Channel (UPC) 196. Each of thetwo transmitters consists of FEC encoder, modulator, frequency agiledigital up converter, RF front-end, etc. to enable upstream bursttransmissions in any channel in the upstream spectrum, according to thestored burst profiles sent from the fsCMTS 102.

[0059] Upstream MAC management burst packets 498 are sent to UCC channeltransmitter 194, which outputted as RF burst signal 490 to the diplexfilter 460. Payload IP packets 488 emerges from upstream processing unit506, accordingly processed by the UPC burst transmitter 196, whoseoutput burst RF signal 480 is coupled to the diplex filter 410 andemerges as a RF signal 405, which is coupled to the HFC coax 402 bysplitter 404, traveling upstream to the head end where the fsCMTS 102 islocated.

[0060] Now the signal flow of the fsCM system 100 between the fsCMTS 102and fsCM 106 has been described. The following further description willshow how the fsMAC-CMTS 124 and fsMAC-CM 192 will coordinate themultiple access transmission of upstream bursts. Essential MACmanagement messages SYNC 500, MDCD 1000, MMAP 900, CREQ 600, CRSP 700,BREQ 800 are described first and then the fsMAC protocol details willfollow.

[0061] Full-Service MAC Management Messages

[0062] SYNC Message

[0063]FIG. 5 is a block diagram of a SYNC MAC message structure 500.SYNC MAC message structure 500 includes a MAC management header 502, atime stamp snapshot 502 that captures the value of the sampled value oftime stamp counter 130, a fsMAC domain identifier 506, and a downstreamchannel identifier 508. A description of the fields of SYNC message 500is shown in Table 1. However, fewer or additional fields could also beused in SYNC message 500. TABLE 1 SYNC MESSAGE 500 Field ParameterDescription of Field Parameter fsMAC Message Header 502 This fieldallows fsCM-MAC 192 to uniquely identify and process the SYNC managementmessage 500. Time stamp snapshot 504 This field contains the sampledvalue of time stamp counter 130. FsMAC domain identifier 506 This fielduniquely identifies the fsMAC domain as defined by MMAP message 900.Downstream Channel identifier This field uniquely identifies the 508downstream channel to which fsMAC messages are transmitted.

[0064]FIG. 6 is a block diagram of a calibration request (CREQ) MACmessage structure 600. CREQ MAC message structure 600 includes a MACmanagement header 602, fsCM service identifier 604, fsMAC domainidentifier 606, downstream channel identifier 608, fsCM Ethernet MACaddress 610, fsCM type 612, and pre-equalizer training sequence 614.

[0065] A description of the fields of CREQ message 600 is shown in Table2.

[0066] However, fewer or additional fields could also be used in CREQmessage 600 in other embodiments. TABLE 2 CREQ MESSAGE 600 FieldParameter Description of Field Parameter fsMAC Message This field allowsfsCM-MAC 192 to uniquely Header 602 identify and process the CREQmessage 600. fsCM service identifier This field uniquely identify theservice flow (SID) 604 associated with the fsCM 106 within the fsMACdomain identified by fsMAC domain ID 606 fsMAC domain This fielduniquely identifies the fsMAC identifier (MAC ID) 606 domain as definedby MMAP message 900. DCPC channel identifier This field uniquelyidentifies the downstream 608 control and payload channel (DCPC) intowhich fsMAC messages are transmitted Ethernet MAC address This fieldcontains the 48-bit Ethernet MAC 610 address associated with the fsCM106 FsCM type 612 This field contains information about the type andversion of the fsCM 106 Pre-equalizer training This field containspre-equalizer training sequence 614 sequence(s) for the fsCM 106transmitters 194, 196.

[0067]FIG. 7 is a block diagram of a calibration response MAC messagestructure 700. CRSP MAC message structure 700 includes a MAC managementheader 702, fsCM service identifier 704, fsMAC domain identifier 706,upstream channel identifier 708, timing adjustment 710, frequencyadjustment 712, transmit power adjustment 714, transmitter pre-equalizertap coefficients 716, and re-assigned fsMAC domain identifier 718.

[0068] A description of the fields of CRSP message 700 is shown in Table3. However, fewer or additional fields could also be used in CRSPmessage 700 in other embodiments. TABLE 3 CRSP MESSAGE 700 FieldParameter Description of Field Parameter fsMAC Message This field allowsfsCM-MAC 192 to uniquely Header 702 identify and process the CRSPmessage 700. fsCM service identifier This field uniquely identify theservice flow (SID) 704 associated with the fsCM 106 within the fsMACdomain identified by fsMAC domain ID 706 fsMAC domain This fielduniquely identifies the fsMAC identifier domain as defined by MMAPmessage 900. (MAC ID) 706 Upstream channel This field identifies theupstream channel identifier 708 CRSP 700 is responding to. Timingadjustment This field contains information for fsCM 106 to 710 adjustits local clock to synchronize with that of fsCMTS Frequency adjustmentThis field contains information for fsCM 106 to 712 adjust its upstreamtransmitter center frequency to within the receiving frequency range ofthe fsCMTS receiver. Transmit power This field contains information forfsCM 106 to adjustment 714 adjust its transmitter power amplifier gainto the correct level. Transmit pre-equalizer This field containsinformation for fsCM 106 to tap coefficients adjust its transmitterpre-equalizer to this 716 new parameters. Reassigned fsMAC This fieldcontains information (if present) domain identifier about a new fsMACdomain identifier, which 718 fsCM 106 will associate with afterreceiving this message.

[0069]FIG. 8 is a block diagram of a bandwidth request (BREQ 800) MACmessage structure 800, which includes a fsMAC message header 802, a fsCMservice identifier 804, a fsMAC domain identifier 806, a framing headertype 808, and amount requested 810.

[0070] A description of the fields of BREQ message 800 is shown in Table4. However, fewer or additional fields could also be used. TABLE 4 BREQMESSAGE 800 Field Parameter Description of Field Parameter FsMAC MessageThis field allows fsCM-MAC 192 to uniquely Header 802 identify andprocess the BREQ message 800. fsCM service This field uniquely identifythe service flow identifier (SID) 804 associated with the fsCM 106within the fsMAC domain identified by fsMAC domain ID 806 fsMAC domainThis field uniquely identifies the fsMAC domain as identifier (MAC ID)defined by MMAP message 900. 806 Framing header This field contains theheader type information for type 806 fsCMTS to take into considerationof the MAC frame header overhead when allocating bandwidth for therequesting fsCM. Amount requested This field contains amount of payloadbandwidth 810 (excluding MAC header overhead) requested by fsCM. E.g.number of bytes or number of time slots such as mini-slots.

[0071]FIG. 9 is a block diagram of a multi-channel bandwidth allocationMAC message (MMAP) structure 900, which includes a fsMAC managementmessage header 902, a fsMAC domain identifier 904, a list of broadcastgrants, a list of unicast grants, and a list of pending grants 910.

[0072] A description of the fields of MMAP message 900 is shown in Table5. However, fewer or additional fields could also be used. TABLE 5 MMAPMESSAGE 900 Field Parameter Description of Field Parameter fsMAC MessageThis field allows fsCM-MAC 192 to uniquely Header 902 identify andprocess the MMAP message 900. fsMAC domain This field uniquelyidentifies the fsMAC domain identifier 904 Broadcast grants 906 Thisfield contains the bandwidth grants for the contention area thatbandwidth requests are transmitted from any fsCM in the fsMAC domain.Table 6 gives an example of the broadcast grants Unicast grants 908 Thisfield contains the bandwidth grants address to an individual fsCM. Table7 gives and example of unicast grants. Pending grants 910 This fieldcontains a list of pending grants for those BREQ's that are successfullyreceived by the fsCMTS, but the grants are deferred to a later MMAP 900.Table 8 gives an example of pending grants

[0073] TABLE 6 Broadcast grants 906 example Broadcast Grants Descriptionof Field Parameter Number of broadcast =2 in this example grants ServiceID (Start of 1^(st) broadcast grant). This field contains the SID of thebroadcast address for all fsCM's. Grant type Bandwidth request BREQ 800Upstream channel ID This field contains the channel ID to which thebroadcast grant is allocated Burst profile ID This field identifies theburst profile of BREQ 800 Back-off start and End This field contains theback-off window of the values chosen contention resolution algorithmLength of payload data BREQ 800 burst payload data length in bytes inbytes Number of bursts Number of BREQ 800 bursts for this grantTransmission start Start transmission time of the first BREQ 800 timeburst Service ID (Start of 2^(nd) broadcast grant). This field containsthe SID of a broadcast address for a group of fsCM's. Grant typeBandwidth request BREQ 800 Upstream channel ID This field contains thechannel ID to which the broadcast grant is allocated Burst profile IDThis field identifies the burst profile of the BREQ 800 Back-off startand This field contains the back-off window End values of the chosencontention resolution algorithm in this example Length of payload dataBREQ 800 burst payload data length in bytes in bytes Number of burstsNumber of BREQ 800 bursts for this grant Transmission start Starttransmission time of the first BREQ 800 time burst

[0074] TABLE 7 Unicast grants 906 example Unicast Grants Description ofField Parameter Number of 3 in this example Unicast grants SID-1 (Startof 1^(st) unicast grant). This field contains SID of fsCM-1. Grant typeVariable length payload packet Upstream channel This field contains thechannel ID to which the unicast ID grant is allocated Burst profile IDThis field identifies the burst profile for packet Burst framing Thisfield contains framing header type to enable header type fsCMTS tocalculate the overhead needed for the burst Length of payload Burstpayload data length in bytes data in bytes Transmission start Starttransmission time of the first BREQ 800 burst time SID-2 (Start of2^(nd) unicast grant). This field contains SID of fsCM-2. Grant typeConstant bit rate (CBR) Upstream channel This field contains the channelID to which the unicast ID grant is allocated Burst profile ID Thisfield identifies the burst profile for this burst Burst framing Thisfield contains framing header type to enable header type fsCMTS tocalculate the overhead needed for the burst Length of payload Burstpayload data length in bytes data in bytes Grant interval This fieldcontains the time interval between two adjacent grants Transmissionstart Start transmission time of the burst time SID-3 (Start of 3^(rd)unicast grant). This field contains SID of fsCM-3. Grant type Dedicatedchannel Upstream channel This field contains the channel ID to which theunicast ID grant is allocated Length of payload Burst payload datalength in bytes data in bytes Grant duration This field contains thetime for which the dedicated channel can be used Transmission startStart transmission time of the first burst time

[0075] TABLE 8 Pending grants 910 example Pending Grants Description ofField Parameter Number of broadcast grants =2 in this example SID-a Thisfield contains the SID of the pending grant for fsCM-a. SID-b This fieldcontains the SID of the pending grant for fsCM-b.

[0076]FIG. 9 is a block diagram of a fsMAC domain channel descriptor(MDCD) MAC message structure 1000, which includes a MAC message header1002, a fsMAC domain identifier 1004, an accept new fsCM registrationflag 1006, number of downstream channels 1008, number of upstreamchannels 1010, downstream channel change count 1012, upstream channelchange count 1014, a list of downstream channel identifiers andType-Length-Values (TLV's) 1026, a list of upstream channel identifiersand TLV's 1028, and a list of upstream burst profile identifiers andTLV's 1030.

[0077] A description of the fields of MDCD message 1000 is shown inTable 9. However, fewer or additional fields could also be used. TABLE 9MDCD MESSAGE 1000 Field Parameter Description of Field Parameter fsMACMessage This field allows fsCM-MAC 192 to uniquely Header 1002 identifyand process the MDCD message 1000. FsMAC domain This field uniquelyidentifies the fsMAC identifier 1004 domain as defined by MMAP message900. Accept-new-fsCM- This field contains a flag bit which registrationflag 1006 when set, indicating the fsMAC domain is accepting new fsCM106 registration. Number of downstream This field contains N number ofchannels 1008 downstream channels in the fsMAC domain. Number ofupstream This field contains M number of upstream channels 1010 channelsin the fsMAC domain. Downstream channel This field contains a count ofchanges in change count 1012 downstream channel configuration. If thisfield is different than the count in the previous MDCD message 1000,fsCM's 106 in the fsMAC domain must update its downstream channelconfiguration to the current MDCD message 1000. Upstream channel changeThis field contains a count of changes in count 1014 upstream channelconfiguration. If this field is different than the count in the previousMDCD message 1000, fsCM's 106 in the fsMAC domain must update itsupstream channel configuration to the current MDCD message 1000. List ofdownstream This field contains a list of N downstream channelidentifiers and channel identifiers and the associated TLV's 1026 TLV'sdefining the channel parameters. Table 10 shows an example of a list of2 downstream channels. List of upstream channel This field contains alist of M upstream channel identifiers and identifiers and theassociated TLV's defining TLV's 1028 the channel parameters. Table 11shows an example of a list of 5 upstream channels. List of upstream Thisfield contains a list of X upstream burst burst profile profileidentifiers and the associated TLV's identifiers and defining the burstparameters. Table 12 shows TLV's 1030 an example of a list of 3 burstprofiles.

[0078] TABLE 10 Downstream channel identifiers and TLV's 1026 exampleNumber of downstream channels = 2 downstream TLV encoding channelparameter Type Length Value type (1 byte) (1 byte) (L bytes) DescriptionDownstream channel 1 1 01 01 (Channel ID) identifier Downstream channel2 1  1 1 (DCPC) type Center frequency 3 4 f1 Hz Symbol rate 4 1  0 0(5.056941 M symbols/sec) FEC 5 1  1 1 (J83 Annex B) Modulation 6 1  0 64QAM Interleave depth (I, J) 7 2 16, 8 Latency = 0.48 ms Downstreamchannel 1 1 02 02 identifier Downstream channel 2 1  2 2 (DPC1) typeCenter frequency 3 4 f2 Hz Symbol rate 4 1  1 1 (5.360537 M symbols/sec)FEC 5 1  1 1 = J83 Annex B Modulation 6 1  1 256 QAM Interleave depth(I, J) 7 2 128, 1 Latency = 2.8 ms

[0079] TABLE 11 Upstream channel identifiers and TLV's 1028 exampleNumber of upstream channels = 5 Upstream TLV encoding channel parameterType Length Value type (1 byte) (1 byte) (L bytes) Description Upstreamchannel 1 1 10 10 identifier Upstream channel 2 1  0 0 (UCCI) typeCenter frequency 3 4 f3 Hz Symbol rate 4 1  0 0 (640K symbols/sec)Upstream channel 1 1 11 Channel ID = 11 identifier Upstream channel 2 1 1 1 (UCC2) type Center frequency 3 4 f4 Hz Symbol rate 4 1  2 2 (320Ksymbols/sec) Upstream channel 1 1 12 Channel ID = 12 identifier Upstreamchannel 2 1  2 2 (UCC3) type Center frequency 3 4 f5 Hz Symbol rate 4 1 3 3 = 640K symbols/sec Upstream channel 1 1 13 Channel ID = 13identifier Upstream channel 2 1  3 3 (UPC1) type Center frequency 3 4 f6Hz Symbol rate 4 1  6 6 = 5.12 M symbols/sec Upstream channel 1 1 14Channel ID = 14 identifier Upstream channel 2 1  4 4 (UPC2) type Centerfrequency 3 4 f7 Hz Symbol rate 4 1  6 6 = 5.12 M symbols/sec

[0080] TABLE 12 Upstream burst profile identifiers and TLV's exampleNumber of upstream burst profiles = 3 TLV encoding upstream burst TypeLength Value parameter type (1 byte) (1 byte) (L bytes) DescriptionBurst identifier 1 1 11 Burst profile 1 Modulation 2 1 0 0 = QPSKPreamble length 3 2 64 64 bytes FEC code word (k) 4 1 78 13 bytes FECerror correction 5 1 6 T = 2 bytes (T) Scramble seed 6 2 35 Seed =00110101 Inter-burst guard time 7 1 5 5 symbols burst identifier 1 1 12Burst profile 2 modulation 2 1 0 0 = QPSK Preamble length 3 2 64 64bites FEC code work (k) 4 1 78 78 bytes FEC error correction 5 1 6 T = 6bytes (T) Scramble seed 6 2 35 Seed = 00110101 Inter-burst guard time 71 5 5 symbols burst identifier 1 1 13 Burst profile 3 Modulation 2 1 0 0= 64 QAM Preamble length 3 2 64 128 bites FEC code work (k) 4 1 78 256bytes FEC error correction 5 1 6 T = 10 bytes (T) Scramble seed 6 2 35Seed = 00110101 Inter-burst guard time 7 1 5 5 symbols

[0081] Full-Service Cable Modem System Operation

[0082] The fsCMTS sets up the fsCM domain consisting of:

[0083] 2 downstream channels

[0084] 1. DCPC is a broadcast channel for all fsCM's within the fsCMdomain and is configured to ITU-T J83 Annex B standard with 64 QAMmodulation and at center frequency of f1 Hz in the downstream spectrumas shown in FIG. 3. This channel is primarily for data-over-cable MACmanagement messages, IP traffic and to a less extent, MPEG-2 videodelivery.

[0085] 2. DPC1 is the a broadcast channel for all fsCM's within the fsCMdomain, is configured to be ITU-T J83 Annex B standard with 256 QAMmodulation and at center frequency of f2 Hz in the downstream spectrumas shown in FIG. 3. This channel is primarily for broadcast qualityMPEG-2 movie delivery, but also carries IP packets.

[0086] 3 upstream control channels

[0087] 1. UCC1 for contention bandwidth request for all or a group offsCM's, is configured to operate at 640 Ksymbols/sec with QPSKmodulation and at center frequency of f3 Hz in the upstream spectrum asshown in FIG. 3.

[0088] 2. UCC2 is for contention calibration and maintenance for all ora group of fsCM's is configured to operate at 320 Ksymbols/sec with QPSKmodulation and at center frequency of f4 Hz in the upstream spectrum asshown in FIG. 3.

[0089] 3. UCC3 is for Aloha contention, pay-per-view or video-on-demandrequest burst for all or a group of fsCM's is configured to operate at640 Ksymbols/sec with QPSK modulation and at center frequency of f5 Hzin the upstream spectrum as shown in FIG. 3.

[0090] 2 upstream payload channels:

[0091] 1. UPC1 is intended primarily for voice-over-IP CBR traffic forall or a group of fsCM's, is configured to operate at 5.12 Msymbols/secwith 16 QAM modulation and at center frequency of f6 Hz in the upstreamspectrum as shown in FIG. 3.

[0092] 2. UPC2 is intended primarily for high-speed data and mediastreaming traffic for all or a group of fsCM's 106 is configured tooperate at 5.12 Msymbols/sec with 16 QAM modulation and at centerfrequency of f7 Hz in the upstream spectrum as shown in FIG. 3.

[0093] When the fsCMTS 102 is operational, the following MAC managementmessages are broadcast periodically to all fsCMs 106 to establish a fsCMdomain, in the HFC 104 via DCPC 147:

[0094] 1. SYNC 500, typically sent every 150 to 250 ms,

[0095] 2. MDCD 1000, typically sent every 1 to 2 seconds, and

[0096] 3. MMAP 900, typically sent every 2 to 10 ms.

[0097] SYNC 500 establishes network-wide clock synchronization of thefsCMTS 102 and fsCM's using a conventional time-stamp methodology and isknown in the art. MDCD 1000 establishes the fsMAC domain using the fsMACdomain identifier 1004. MDCD 1000 also contains the parameters needed byfsCM's to join the fsMAC domain by setting up the channel and burstprofiles. MMAP 900 contains information about upstream transmissionopportunities on a specific channel, using a specific burst profile,duration of the transmission, and at a specific start time to transmit.MMAP 900 also contains upstream transmission opportunities, typicallyonce every 1 to 2 seconds, for fsCM 106 that wishes to join the networkto transmit CREQ 600 to adjust its ranging offset, center frequency,transmitter power level, and transmitter pre-equalizer coefficients aspart of the initialization process. Once initialized, fsCM 106 starts touse contention-based CREQ 600 to request transmission of payloadpackets.

[0098] Full-Service Cable Modem Initialization

[0099] Referring to FIG. 10, a fsCM 106 initialization flow diagram 1100is entered at block 1102 when the fsCM 106 is powered up or reset. Inblock 1104, DCPC receiver 470 at fsCM 106 is continuously searching fora valid DCPC channel. The DCPC is considered as valid if MPEG-2 TS witha valid data-over-cable PID (e.g. 1 FFE hexadecimal) and once found,block 1106 is entered to search for a valid MDCD 1000. In MDCD 1000, theflag 1006, if set, signifies that the DCPC is accepting new fsCM 106registrations, and block 1110 is entered. If flag 1006 is not set,signifying the MDCD 1000 is not taking in new registrations, fsCM 106will exit block 1106 and enter block 1104 for searching for anothervalid DCPC.

[0100] At block 1110, all the parameters in MDCD 1000 are accepted bythe fsCM 106. The fsMAC domain ID 1004 will be used to match the domainidentifier 506 in SYNC 500 in block 13. If the valid SYNC 500 isreceived, the fsCM 106 will synchronize its time base with the fsCMTStime base (block 1110). The fsCM 106 initializes the other downstreamand upstream channels, the burst profiles, based on information receivedin MDCD 1000 and enters block 1116.

[0101] In block 1116, fsCM 106 monitor MMAP 900 for broadcastcalibration grant as shown in Table 6. In this example, the secondbroadcast grant is for CREQ 600 (block 15). If a CREQ grant is received,fsCM 106 will construct a calibration burst based on the burst profile,and length of payload information in broadcast grant 906 (block 1118).

[0102] In block 1120 the CREQ 600 burst will then be transmitted at thespecified upstream channel at the specified transmission start time(subject to back-off based on the back-off start and end valuesspecified in the grant using exponential back-off algorithm). If acalibration response CRSP 700 is received by fsCM 106 in block 1122, theinitial calibration is successful and fine calibration block 1124 isentered. If no CRSP 700 is received in block 1122, after apre-determined time-out, block 1116 will be entered and the CREQ 600process will be retried.

[0103] In block 1124, fsCMTS will do fine calibration on each of theupstream channels in the fsCM domain by sending a periodic unicast finecalibration grant to the fsCM 106 for each upstream channel. In block1124 the fine-calibration process is complete after receiving fine CRSP700 from fsCMTS and after fsCM 106 adjusts its upstream channelparameters ranging offset, frequency, power level, and pre-equalizercoefficients. These parameters will be saved in the fsCM 106 upstreamchannel profiles and they will be used to configure the channel beforeburst transmission. After fine calibration, block 1126 is entered. fsCM106 completes the modem registration process and becomes operational inblock 1128.

[0104] Transmission Using Bandwidth Request

[0105] Referring to FIG. 11, which is a flow diagram of transmissionusing contention-based bandwidth request 1200. In block 1204, one ormore packets are queued up at fsCM 106. In block 1206 fsMAC-CM 192chooses one or more of packets to transmit. The number of bytes ofpayload and header type (e.g. short, long or concatenated) isdetermined. In block 1208, fsCM 106 waits until MMAP 900 is receivedwith BREQ 800 broadcast grant 906 (example in Table 6). Entering block1210 fsCM 106 uses the back-off start and end values to calculate theinitial back-off of burst transmission (any back-off algorithm will workand is well-known in the art). If the back-off algorithm determines thetransmission opportunity is beyond the current grant, fsCM 106 willdefer the transmission to the next MMAP 900; otherwise, referring toTable 6, 1^(st) broadcast grant, fsCM 106 calculates the CREQ 600 bursttransmission start time according to:

[0106] (Transmission start time)+

[0107] (Burst duration calculated and based on the length of payload andheader in bytes and burst profile)×(number of burst deferred calculatedby the back-off algorithm).

[0108] BREQ 800 will be transmitted at the calculated time at thechannel specified by the upstream channel ID. Block 1212 is entered andfsCM 106 waits for a unicast grant or a pending grant in the next MMAP900. The next MMAP 900 is received in block 1218 and is checked for aunicast grant with a SID corresponding to the one in the original BREQ800 (block 1220). The unicast grant will have the necessary information(burst profile, header type, and burst profile) to assemble a burst(block 1226) and transmit at the specified upstream channel at thespecified transmission start time (block 1228). If in block 1220, nounicast grant is received for the BREQ 800, MMAP 900 is checked forexistence of a pending grant.

[0109] In block 1224, if there is a pending grant, block 1218 is enteredto wait for the next MMAP 900. If in block 1224, there is no pendinggrant in the MMAP 900, the CREQ 600 is considered as lost or collided,and block 1208 is entered to retry the BREQ 800 transmission.

[0110] True Seamless Channel Change

[0111] In a conventional data-over cable system, a conventional cablemodem termination system (CMTS) may direct a cable modem (CM) to changeits upstream channel for traffic load balancing, noise avoidance, orfailed channel backup. The procedure for performing a channel change isas follows. When the CMTS determines to move a CM from the currentlyassigned upstream channel to another, it sends a channel change requestmessage to the CM. In response, the CM transmits a channel changeresponse message on the currently assigned channel to signal itsreadiness to use the new channel. After switching to the new channel,the CM typically performs recalibration of transmitter parameters suchas ranging offset, power level, frequency and pre-equalizer coefficientsbefore the CM can use the new channel. Such a channel switchingmechanism can be very time-consuming and can take seconds or morebecause a complete re-calibration is often required.

[0112] According to this invention, a true seamless channel change canbe achieved in the fsCM system 100. True seamless channel change meanson a packet-by-packet basis, each CMTS-directed cable modem bursttransmission can be at any one of the upstream channel, configured withany one of the burst profiles as defined by the fsCMTS domain in thefsMAC message MDCD 1000.

[0113] The fsCM 106 joins a fsCM domain accepting new registrations inthe MDCD message 1000, which also contains fields for a list ofdownstream channels with channel profile parameters, a list of upstreamchannel parameters and channel profile parameters, and a list of burstprofile parameters. These profile parameters are uniquely identifiedwithin the fsMAC domain using downstream, upstream and burst ID's. Theseparameters are stored in the fsCM, together with the channel calibrationparameters for each channel as a result of calibration request/responseprocess.

[0114] When an upstream transmission grant is received from the MMAPmessage 900, the grant contains sufficient information abouttransmission channel ID, burst profile, size of granted and header typeto form an upstream burst to be transmitted at the exact start timespecified in the same MMAP message 900. Thus the channel change isimmediate and truly seamless.

[0115] Alternative Embodiments

[0116] One skilled in the art can take advantage of the multi-channelfsMAC in different variations for further optimization. Examples are:

[0117] Use all downstream channels for IP packet streams, if MPEG-2video is not needed, to further boost downstream capacity for additionalusers, or can be for IP media streaming.

[0118] Use a single upstream control channel for channel calibration andbandwidth requests.

[0119] Define different upstream payload channels, such as CBR channel,dedicated channels to achieve quality of service and capacity goals.

[0120] Although the teachings of the invention have been illustratedherein in terms of a few preferred and alternative embodiments, thoseskilled in the art will appreciate numerous modifications, improvementsand substitutions that will serve the same functions without departingfrom the true spirit and scope of the appended claims. All suchmodifications, improvement and substitutions are intended to be includedwithin the scope of the claims appended hereto.

What I claim as my invention is:
 1. A full-service cable modem networksystem comprising: (a) a full-service cable modem termination system ata head end, (b) a plurality of full-service cable modems at remotecustomer premises, wherein a full-service-media-access control domain,further comprising of at least two downstream channels, and at least twoupstream channels, wherein one of the said downstream channels carriesmedia-access-control management messages, wherein at least one of thesaid upstream channel carries calibration and bandwidth requestmanagement messages, and wherein at least the other said upstreamchannels carries payload packet stream.
 2. The network system of claim 1wherein the said two downstream channels carries both MPEG-2 transportpacket stream and data-over-cable Internet Protocol packet stream, 3.The network system of claim 1 wherein said network system is saiddownstream channels simultaneously carry any mix of MPEG-2 transportstreams and Internet Protocol packets.
 4. The network system of claim 1wherein each channel has its own unique frequency, bandwidth, modulationscheme and burst profiles.
 5. A method for enabling a full-service cablemodem termination system to communicate with a plurality of full-servicecable modems via a multi-channel shared media multiple access networkcomprising the steps of: (a) broadcasting, via a first downstreamchannel, a first media-access-control (MAC) management message with aMAC domain identifier and an indication of accepting new registrationsfrom said cable modems at a first upstream channel, (b) broadcasting asecond MAC management message with the same said MAC domain identifieras in step (a), granting said cable modems each to transmit acalibration MAC management message in said first upstream channel, (c)receiving a calibration request from said cable modem in said firstupstream channel, and in response, transmitting a calibration responseto said cable modem via said first downstream channel, (d) in furtherresponse, transmitting at least a second calibration transmit grant MACmessage, for at least a second upstream channel, in said second MACmanagement message, in said first downstream channel, to said cablemodem, (e) receiving a second calibration request from said cable modemfor said second upstream channel, (f) in response, transmitting a secondcalibration response for said second upstream channel to said cablemodem, via said first upstream channel, (g) receiving a bandwidthrequest MAC message via first upstream channel from said cable modem,(h) in response, transmitting a payload transmit grant in said secondMAC management message in said first downstream channel to said cablemodem to transmit said payload packet at said second upstream channel,with a burst profile, at a transmit start time, specified in said secondMAC management message.
 6. The method of claim 5 wherein at step (a),said first MAC management message also contains a channel identifier anda channel profile of at least a second downstream channel
 7. The methodof claim 6 wherein said second downstream channel carries MPEG-2transport stream packets and Internet Protocol packet.
 8. The method ofclaim 5 wherein at step (a), said first MAC management message containsa list of channel identifiers with channel profile parameters.
 9. Themethod of claim 5 wherein at step (a), said first MAC management messagealso contains a list of upstream burst identifiers with burst profileparameters.
 10. The method of claim 5 wherein at step (b), said secondMAC management message contains a list of channel identifiers withchannel profile parameters.
 11. The method of claim 5 wherein at step(a) time-stamp synchronization MAC messages with said MAC domainidentifier is transmitted in said first downstream channel.
 12. Themethod of claim 5, said multi-channel shared media multiple accessnetwork is a conventional two-way hybrid fiber-coax cable televisionnetwork.
 13. A method for enabling a full-service cable modem tocommunicate with a full-service cable modem termination system via amulti-channel shared media multiple access network comprising the stepsof: (a) initializing by locking to a valid first downstream channel, (b)receiving a media-access-control (MAC) domain identifier from a firstMAC management message in said first downstream channel, (c) thenobtaining a calibration transmit opportunity in a first upstream channelfrom a second MAC management message in said first downstream channel,(d) transmitting a calibration MAC message at said first upstreamchannel, (e) receiving a calibration response MAC message for said firstupstream channel, from said first downstream channel, (f) receivingadditional calibration transmit opportunity for at least a secondupstream channel and performing channel calibration on said secondupstream channel, (g) responding to receipt of a transmit grant fromsaid second MAC management message in said first downstream channel,transmitting a payload packet at said second upstream channel, with aburst profile, at a transmit start time, specified in said second MACmanagement message.
 14. The method of claim 13 wherein after step (b),obtaining at least a second downstream channel identity from said firstMAC management message, and starting to receive MPEG-2 transport streampackets and Internet Protocol packet streams in said second downstreamchannel.
 15. The method of claim 13 wherein at step (a), said validfirst downstream channel is a downstream control and payload channelwith transmitted MAC management messages.
 16. The method of claim 13wherein at step (b), said first MAC management message contains anaccepting-new-registration flag with a set value.
 17. The method ofclaim 13 wherein at step (b), said first MAC management message containsa list of channel identifiers with channel profile parameters.
 18. Themethod of claim 13 wherein at step (b), said first MAC managementmessage contains a list of upstream burst identifiers with burst profileparameters.
 19. The method of claim 13 wherein at step (c), said secondMAC management message contains a list of channel identifiers withchannel profile parameters.
 20. The method of claim 13 wherein furthercomprising the steps of: (h) after step (b) but before step (c),receiving time-stamp synchronization MAC messages with said MAC domainidentifier matching said MAC domain identifier obtained in step (b), andcompleting the time synchronization with said cable modem terminationsystem.
 21. The method of claim 13, said multi-channel shared mediamultiple access network is a conventional two-way hybrid fiber-coaxcable television network.
 22. A circuit for enabling a full-servicecable modem termination system to communicate with a plurality offull-service cable modems via a shared-media network comprising: (a) atleast two downstream channel transmitter for transmitting both MPEG-2transport packet streams and IP packet streams, (b) at least twoupstream channel burst receivers, (c) a full-servicemedia-access-control circuit, wherein said first receiver is forreceiving calibration and bandwidth request messages, and said secondreceiver is for receiving payload packets.
 23. The circuit of claim 22further comprising an Internet Protocol network interface, connected tosaid media-access-control unit.
 24. The circuit of claim 22 furthercomprising a time stamp generator connected to the media-access-controlunit.
 25. The circuit of claim 22 wherein said network is a two-wayhybrid fiber-coax cable television network.
 26. The circuit of claim 22wherein said media-access-control circuit generates said managementmessages that are encapsulated as data-over-cable MPEG-2 transportstreams, and are transmitted through said first downstream transmitter.27. The circuit of claim 22 wherein said media-access-control circuitgenerates synchronization management messages from a time stampgenerator and are encapsulated as data-over-cable MPEG-2 transportstreams, and are transmitted through said first and said seconddownstream transmitters.
 28. The circuit of claim 22 wherein saidmedia-access-control forwards IP packets from said IP network interfaceunit, and are encapsulated as data-over-cable MPEG-2 transport streams,and are transmitted through said first and second said downstreamtransmitters.
 29. The circuit of claim 22 wherein said first and saidsecond transmitters transmit MPEG-2 transport stream packets from atleast one video server.
 30. The circuit of claim 22 wherein the said twotransmitters are capable of transmitting both MPEG-2 transport packetstreams and Internet Protocol packet streams.
 31. The circuit of claim22 wherein said first transmitter transmit multi-channel channeldescriptor media-access-control messages in the downstream control andpayload channel for establishing a full-service media-access-controldomain, identifying channels with unique identifiers and channel profileparameters, and identifying and specifying burst profiles.
 32. Thecircuit of claim 22 wherein said first transmitter transmitsmulti-channel bandwidth allocation media-access-control messages to thedownstream control and payload channel for allocating bandwidth grantsto said cable modem; said grant could be a unicast grant, a broadcastbandwidth request grant, or a broadcast calibration grant, or a pendinggrant.
 33. The circuit of claim 22 wherein said second transmittertransmits broadcast quality MPEG-2 transport streams and data-over-cableIP streams to the downstream payload channel.
 34. The circuit of claim22 wherein at least a first burst receiver receives media-access-controlmessages and forward them to said media-access-control unit.
 35. Thecircuit of claim 22 wherein at least a second burst receiver receivespayload packet streams and forward them to said media-access-controlunit.
 36. The circuit of claim 22 wherein each channel has its ownunique frequency, bandwidth, modulation scheme and burst profiles.
 37. Acircuit for enabling a full-service cable modem to communicate to afull-service cable modem terminating system via a shared-medium networkcomprising: (a) at least two receivers for receiving both MPEG-2transport packet streams and IP packet streams from at least twodownstream channels, (b) at least one upstream burst transmitter fortransmitting media-access-control management packets and payload packetstreams into at least one upstream channel, (c) a full-servicemedia-access-control circuit, (d) a customer premises interface, and (e)a MPEG-2 transport stream de-multiplexing unit.
 38. The circuit of claim37 wherein said network is a two-way hybrid fiber-coax cable televisionnetwork.
 39. The circuit of claim 37 wherein the said two receivers arecapable of receiving both MPEG-2 transport packet streams and InternetProtocol packet streams.
 40. The circuit of claim 37 wherein furthercomprising a MPEG-2 transports stream de-multiplexing circuit toseparate data-over-cable packet streams from conventional MPEG-2transport streams by a unique packet identifier.
 41. The circuit ofclaim 37 wherein further comprising a full-service media-access-controlunit for co-ordination of multiple access upstream transmissions. 42.The circuit of claim 37 wherein further comprising a customer premisesequipment interface which communicates with equipment capable of any mixof data, voice, and video.
 43. The circuit of claim 37 wherein furthercomprising a MPEG-2 transport stream interface for conventional MPEG-2decoders or digital set top boxes for delivery of broadcast qualitymovies and other audiovisual contents.
 44. The circuit of claim 37wherein said first receiver receives synchronizationmedia-access-control messages from the downstream control and payloadchannel for time synchronization of local time with that of saidfull-service cable modem termination system.
 45. The circuit of claim 37wherein said first receiver receives multi-channel channel descriptormedia-access-control messages from the downstream control and payloadchannel for establishing a full-service media-access-control domain,identifying channels with unique identifiers and channel profileparameters, and identifying and specifying burst profiles.
 46. Thecircuit of claim 37 wherein said first receiver receives multi-channelbandwidth allocation media-access-control messages from one of saidchannels for allocating bandwidth grants to said cable modem; said grantcould be a unicast grant, a broadcast bandwidth request grant, or abroadcast calibration grant, or a pending grant.
 47. The circuit ofclaim 37 wherein said transmitter, upon receiving a transmission grant,transmits a burst with a specified burst profile identified by a burstchannel identifier; at a channel center frequency specified by a channelprofile, at a specified transmission time if said grant is a unicastgrant, or at a derived start transmission time calculated from saidspecified transmission start time, said burst profile, a back-off startand stop time, and a conventional back-off algorithm.
 48. The circuit ofclaim 37 wherein said full-service cable modem is capable of deliveringeither or both broadcast quality MPEG-2 digital movies using MPEG-2transport streams or Internet Protocol media streaming packets viaeither or both of said downstream channels.
 49. A method for enabling afull-service cable modem termination system to perform true seamlesschannel change in a full-service cable modem in a multi-channelshared-medium network comprising the steps of: (a) transmitting amedia-access-control channels descriptor message via a downstreamcontrol and payload channel, to said cable modem, via said network, (b)after occurrence(s) of (a), transmitting a unicast transmission grant ina multi-channel bandwidth allocation media-access-control message viasaid downstream control and payload channel, to said cable modem, viasaid network, (c) said grant instructing said cable modem to transmit aburst with a specified burst profile identified by a burst channelidentifier; at a channel center frequency specified by a channelprofile, and at a transmission start time.
 50. The method of claim 49wherein said channels descriptor message containing: a full-servicemedia-access-control domain, a list of channel identifiers and channelparameters, and a list of upstream burst profiles with parameters. 51.The method of claim 49 wherein said unicast transmission grantcontaining: a upstream channel identifier, a burst profile identifier,and a transmission start time,
 52. The method of claim 49 wherein saidburst profile including parameters such as, illustratively, inter-burstguard-time, preamble pattern, interleave factor, forward errorcorrecting code, code word length,
 53. The method of claim 49 whereinsaid channel profile including parameters such as, illustratively,symbol rate, center carrier frequency, modulation format, andpre-equalizer coefficients.
 54. The method of claim 49 whereinburst-by-burst transmission could be of different burst profiles, at achannel with a channel profile, or channels with different channelprofiles.
 55. A method for enabling a full-service cable modem toperform true seamless channel change for a multi-channel shared medianetwork comprising the steps of: (a) receiving a media-access-controlchannels descriptor message via a shared media from a downstream controland payload channel, (b) after occurrence(s) of (a), receiving a unicasttransmission grant from a multi-channel bandwidth allocationmedia-access-control message via said network from said downstreamcontrol and payload channel, (c) transmitting a burst with a specifiedburst profile identified by a burst identifier; at a channel centerfrequency specified by a channel profile and identified by a channelidentifier, and at a transmission start time.
 56. The method of claim 55wherein said channels descriptor message containing: a full-servicemedia-access-control domain, a list of channel identifiers and channelparameters, and a list of upstream burst profiles with parameters, 57.The method of claim 55 wherein said unicast transmission grant containssaid burst identifier, said channel identifier, and said transmissionstart time,
 58. The method of claim 55 wherein burst by bursttransmissions could be of different burst and channel profiles